1. Field of the Invention
The present invention relates to a substrate processing apparatus, a substrate processing method, and a storage medium storing a computer program for performing the substrate processing method. In particular, the present invention relates to a substrate processing apparatus, a substrate processing method, and a storage medium storing a computer program for performing the substrate processing method, which are capable of reducing oxygen dissolved in a chemical liquid so as to improve processing efficiency of a substrate and to improve reliability.
2. Description of Related Art
There has been conventionally known a substrate processing apparatus configured to clean a substrate such as a semiconductor wafer or a glass substrate for LCD (herein referred to simply as “wafer”), by immersing the wafer in a cleaning liquid such as a deionized water or a chemical liquid (e.g., hydrogen fluoride, HF) stored in a cleaning tank (see, JP11-97403A, for example). In such a substrate processing apparatus, the chemical liquid is stored in a chemical-liquid storing container. When a wafer is cleaned with a chemical liquid, the chemical liquid is supplied from the chemical-liquid storing container into the cleaning tank, so that an oxide film on a surface of the wafer is etched. In addition, a deionized water is stored in a deionized-water storing container. When a wafer is cleaned with a chemical liquid, the deionized water is supplied from the deionized-water storing container into the cleaning tank. Further, when a wafer is cleaned with a deionized water, the deionized water is supplied into the cleaning tank, so that the wafer is cleaned (rinsed) with the deionized water.
When oxygen is dissolved in the deionized water to be supplied into the cleaning tank, there occurs a problem in that an oxide film is formed on the surface of the wafer by the oxygen. Thus, the deionized water is generally deaerated beforehand so as to reduce oxygen dissolved in the deionized water.